Find out which of your Facebook friends use iPhones, iPads and Android devices

So you've made a great iPad app, and you want to tell your friends about it. However, you can't remember which of your friends have iPhones, iPads, or Android devices. It's annoying to send your friend a link to an app which they can't run!

Facebook recently announced that the Graph API now includes a new field for users called "devices". This looks something like this: